[james54321]

There was a recent android system update for my nexus 7 2013 from the previous version to 5.0.1.

I'd like to go back to what I had, before the UI completely changed. I've looked at explanations but I'm not used to how android works and its all above my head. Can anyone explain how to do this for me? Or give me any advice?

[JurajO]

Hi, I don't know about any simple way to downgrade a firmware. You can still flash your device and put there basically any firmware you want. It's not exactly easy if you do it first time but you can find many step-by-step tutorials on how to do it, simply google the version you want and I'm sure you can find some.
Hope this helps a bit

[Rukbat]

There's no "go back" or "restore" - updating replaces code already in the phone with new code. Some apps can have the updates removed, but Android itself can't. You''ll have to find a 5.0 ROM for your phone, your country and your carrier, and flash it.